Ouch. No speech in attract mode is a bad sign. I think I have mine sent via MPU switches to once every 4 mins. Try a couple different options. The speech is generated by SC01a ic which is in the lower left corner of board as mounted in game. It is socketed. You could carefully very carefully with static grounding and such. Remove clean pins and socket and re seed it.
But if you have any call outs at all don't touch it and look at other things like connectors connectors connectors.

The voice chip if out is expensive and hard to come by. I had mine out for about a,year and a half til I could find one.

A few years back a guy was selling a few hundred NOS on eBay so some guys picked up a spares so they are out there but expect to pay 20-60$ for it. If willing to part with it.